Psalm 89:28 in the King James Version
My mercy will I keep for him for evermore, and my covenant shall stand fast with him.
Context
27 I will also appoint him my firstborn, the highest of the kings of the earth.
28 I will keep my loving kindness for him forever more. My covenant will stand firm with him.
29 I will also make his offspring endure forever, and his throne as the days of heaven.